eninsula de uanacahabibes Figure 1. AGRRA survey sites in Maria la Gorda, Cuba. See Table 1 for site codes.

Transcription

1 eninsula de uanacahabibes Figure 1. AGRRA survey sites in Maria la Gorda, Cuba. See Table 1 for site codes.

2 RAPID ASSESS 13s- OF NAXT SOUTHEAST ENSENADA DE COIIRIENTES, CUBA (PART 2: REEF FISHES) RODOLFO CLARO' and KAREL CANTELAR RAMOS'.\TI assessment of fish community structure was carried out in the fringing ri-cf at Maria la Gorda in the Ciuanacahabibes I3iosphere Reserve, following the Athntic and Gulf Iiapid Reef Assessn~ent protocols. Quantitative "all species" survq s nere also take11 for comparison with existing inhrmation elsewhere. Unexpectedly for a no-take reserve. fish density and biomass were very low in coinpariso:~ with other Cuban rcefs. In the two shallower (5-8 rn) reefs, parrotfishes and grunts were numerically dominant, and grunts were dominant in teriiis of biomass, but most were small-sized species. A balistid (hfelichthys niger) dominated one of the deeper (9-10 m) reefs. Groupers and most snappers were uncommon at all depths. The scarcity of medium- and large-sized fishes is a consequence of illegal fishing in the reserve. Reduced predation by piscivores may also have caused the proliferation of damselfishes, some of which are killing corals and may be facilitating the spread of coral diseases. The leeward fringing coral reef at Maria la Ciorda, a small resort in the Peninsula de Cuanahacabibes Biosphere Reserve in western Cuba, is considered one of the nation's most beautiful and best conserved. The only tourist facility, which has 29 rooms and belongs to a scuba diving resort, is located near the southeastern tip of Ensenada de Corrientes (Fig. 1). Not far from this resort is a small settlement with 22 houses, a frontier guard-post, a visitor's center for the reserve, and a meteorological radar station. There are fewer than 200 inhabitants (including tourists) during the high tourism season (about six months of the year). The Reserve has been a no-take area for fishing since 1996 by a Resolution of the Ministry of Fishing Industry. Hence its coral reefs would be expected to have a relatively intact fish population. However, there is no existing quantitative information regarding the fish communities in this area. '~nstituto de Oceanologia, Ministerio de Ciencia, Tecnologia y Medio Ambiente, Ave l wo Reparto Flores, Playa, Ciudad de La Habana, CP 12100, Cuba. rclaro@oceano.inf.cu

3 coastline, rise 1-2 m above a gently sloping sandy terrace between depths of 5 and 15 m. Live stony coral cover and the density of "large" (225 cm diameter) colonies were both considered moderate in July 1999, slightly higher at 5-6 m in two shallow lobes (5-6 m) than in two deeper lobes (8-11 m), and dominated by Montas fr-crtw annzilaric, A4 fi.anl{s i, Siderastrea s idereu and A4 faveo lata (Alcolado et al., this volume). Nevertheless, the preferred dive sites for tourists are on the higher relief, structurally more complex, and biologically more diverse reefs that are located at depths of20-30 m along the outer margin of the terrace. The topography on the reef lobes is vely irregular, potentially providing plenty of shelter for tishes and mobile invertebrates. Fishermen who have worked for inany years in the area and local villagers emphasized that, until about 20 years ago, the fringing reef supported numerous. large- and n~edium- sized predatory fishes such as snappers (lutjanids), groupers (serranids), and large-sized parrotfishes (scarids). aria la Gorda area was traditionally fished by commercial fishermen using such artisanal fishing gear as fish traps and hooks and lines. Eventually, non-commercial tishers began to use spearguns. Illegal speargun and hook-andline fishing increased during the early 1990s due to the economic crisis in the country. Small-scale commercial fishing currently occurs outside the reserve, where a few tourists are probably also allowed to fish. The latter is not significant, but due to the small size of the reserve, resident fishes can be harvested close to its boundaries during their local migrations. Illegal subsistence fishing, practiced by local residents and outsiders, continues within and outside the reserve, due to a low level of enforcement of the regulations. Located approximately eight kill southwest of the reserve's boundary, at a depth of m in Cabo Corrientes. is a well-known spawning site for mutton snapper (Li!tjan~!s crnalis) in June, cubera (L. ryanoptems) and dog snapper (L. jocu) in July-August, Nassau grouper (Epinephelus,striatu,s) in December- January, plus black grouper (Mycteroperca bonaci) and yellowfin grouper (M venenosa) in January-March. These aggregations are fished mainly with hooks and lines and fish traps (Claro and Lindeman, in press). The objective of this paper is to contribute to the assessment of reef condition at Maria la Gorda by examining the status of the fish community and its relationship to impacts. METHODS The reef at Maria la Gorda was strategically chosen on the basis of its reputation among divers. Four fish surveys were carried out at two depths (5-8 m and 9-13 m) on representative fore-reef lobes in July 1999 (Table 1). Fishes were visually censused using the Atlantic and Gulf Rapid Reef Assessment (AGRRA) Version 2.2 protocols (see Appendix One, this volume), modified as described below. Quantitative data for the AGRRA fishes in each reef were collected along six belt transects, each 50-m long x 2 m wide, provided quantitative data for the AGGRA fishes in each reef. The transect tape was

4 set on the siibstratuin by tlie dive7;and the c serranids were restricted to species of Epinephelus and Mycteroperca; scarids and haelnulids (grunts) less than 5 cm in length were not tallied. All surveys were made between 10:OO and l7:oo hours by two divers. For identifications, we used Hu~nann's (1994) guide to reef fishes. Leatherjackets were classified according to Eschmeyer's (1998) revision, in which Balistes and Melichthys are in the Balistidae, while Aluterus and Cantherhines are assigned to the Monacanthidae. Biomass estimates of the AGRRA fishes were made using the length-weight relationships given by Garcia-Arteaga et al. (1997) for Cuban fishes. A ranking index (% sighting frequency x % abundance) was calculated for the 25 most abundant of these fishes (data summed over all sites). Species diversity (H'), richness (IP,), and evenness (J) indices for all lish species were estimated on the basis of two qualitaeivc, 30-minute roving diver surveys in each reef. We made six additional "'all species9' belt transects (each 50 m long x 2 in wide) to count and estimate sizes of all fishes in three of the reefs, to compare with similar surveys made at 15 m depth in 16 sites of the Archipelago 10s Canarreos (SW Cuba) in Even though the data are not fully comparable statistically, due to the small sample size at Maria la ~orda, the comparison may serve as a primary reference for assessing current conditions in Maria la Gorda's population of reef fishes. Fish Diversity A total of 88 fish species (Table 2) were found during the eight roving diver censuses (mean = 58lreef, sd= 6). Relative to the two shallow reefs, estimates of species diversity and evenness in the two deeper reefs were slightly lower, while species richness estimates were slightly higher. The most frequently sighted and abundant of these species were the blue chromis (Chromis cyanea), bluehead wrasse (Thalassoma brfclsciatum), and bicolor damselfish (Stegastes partitus) (Table 3). In the "all species" belt transects, there were species per reef (for a total of 71 species). Between 25 and 29 of the AGRRA species were seen in the AGRRA belt transects in each reef (total =45). Highest in the AGRRA hierarchy index were French grunt (Haemulo~zflavolineatum), striped parrotfish (Scarus iserti, =S. croicensis, see Eschmeyer, 1998) and blue tang (Acanthurus coeruleus) (Table 4). Fish Density The total density of the AGRRA fishes (Table 5) was nearly identical in the two shallower reefs (-30.3 and individuals1100 m2) but more variable in the two deeper reefs (-20.3 and 37.5 individuals/100 m2). Herbivorous fishes, primarily small-sized parrotfishes, comprised over half (-52%) of the total numerical count while grunts constituted the second most abundant family overall (Fig. 2). Striped parrotfish dominated in one of the shallow reefs (Sh-1), whereas French grunts were predominant in

5 (Acunth~~rus cowuleus) predornina snapper (Ocyurus C~I;VSII~US) were also moderately cornlnon. Thc second deeper reef (D- 2) had the fewest fishes overall and lacked dominance by any species. Surgeonfishes (acanthurids) were slightly more abundant in the two deeper reefs than in the shallower reefs. Densities of snappers, angelfishes (pomacanthids), butterllyfishes (chaeotodontids), and select groupers (Epiwjdze1u.s and :b!jictcroperca) each totaled --6 individuals1100 m2 for the four reefs. However, a larger number of snappers (0. CIII~SIII.IIF and Lllzjurzzrs upod~rs) Lvere observed closc to the edge of the reef (and outside the area covered by the belt transects) during the roving divcr ccnsuszs nt one of'the decpcr reefs (Dl). Figure 2. Mean fish density (no, individuals11 00 ill% sd) for.agrra fishcs in Maria la Gorda, Cuba. Other = Bocliariu.~ rxfiis, CLIIYIIIS rlrher., L~chr~oluirrrrr.~ rnc~xirnrrs, :~~fic~r-os~~trt~~ociori ~I~~~I:.SUI~LI.S., S~~hyraena barracuda. The mean density of fishes in the "all species" belt transects was nearly 20 times greater than that of the selected species in the AGRRA fish tsansects (541 versus -30 individuals1100 in2). Damselfishes (pomacentrids) were the most abundant family with a mean density of 126 individuals11 00 m2, and most (>93%) of these were bicolor damself%h (Table 6). At approximately 36 individuals1100 m2, the average density of herbivores (all parrotfishes and surgeonfishes, Microspathodon ch~ysurtrs) was almost 20 times greater than the average density of carnivores (all snappers, Epinephelus, Mycteroperca), of which there were only 2.6 individuals1100 nl2.

6 Figure 3. Size frequency distribution (in cm) of herbivores jacanthurids, scarids 25 cm, Microsparhodon chysirrtrs) in Maria la Gorda, Cuba. Shallow N = Deep = 78 n >40 Size Categories 30 Shallow N = 27 Deep N =36 20 n Figure 4. Size frequency distribution in cm of carnivores, as (A) all lutjanids and haemulids 25 cm, select serranids and (B) all lutjanids and select serranids, in Maria la Gorda, Cuba.

7 Most of the key herbivores (acanthurids, scarids 25 cm, Microsprrthodon ch~y.s~i~-~i.s) were less than 20 cm in total length (Fig. 3). Large-sized parrotfishes (such as SCUYZIS gzlucrrnzuin and S. coelestinzw) were absent from the AGGRA belt transects, and most of the surgeonfishes were also small-sized. Regardless of whether or not grunts are included with the ltey AGRKA carnivores, most predatory fishes were in the cm size class in the two shallower reefs and somewhat larger (21-30 cm) in the two deeper reels (Fig. 4A,B). Fish Biomass 'The ioiul hiomas5 of the AGIIRA fishes ('Table 7) ranged from 3,3 12 g/100 m' (m f>-2, which had the li-\vest i'ishes) to 7,502 g1100 m'(in I)-I, whcre ~t was elevated by thc presence of the yzllowtail snapper and black durgeon). Despite their similar densities, the tn o shallower rcef's diffkred somewhat in biomass due to their diff'ering species compositio~:, the French grunts in Sh-2 being slightly larger than the striped parrotfish in Sh- 1. 'The ltey herbivores overall constituted 29% of the total fish biomass. The biomass of grunts was greater in shallow water, whereas the biomass of black durgeon, surgeonfishes and, to a lesser extent, the AGRRA-listed groupers (Epinephelus, M~1cteroperca, were higher in the deeper reefs (Fig. 5). In the "all-species" surveys, the total fish biomass equaled 8,620g1100 m2, of which 3,256 and 499 gil00 m' respectively, were comprised of the herbivores (many of which were small-sized scarids) and carnivores (Table 6). T a Shallow n = 369 Figure 5. Mean fish biomass (grams/loom' + sd) for AGRRA fishes in Maria la Gorda, Cuba. Other = Bodiat7us rzijiis, Caranx ruber, Lachnolaimus maxirnus, Microspathodon chrysurus, Sphyraena barracuda.

8 The macroalgal index (data from Alcolado et al., this volume) had a significant (r' = 0.52, p =0.95) inverse relationship with herbivore density, but showed no relationship with total herbivore biomass (Fig. 6) M acroaigil index r - M acroalpl index 200 Figure 6. Regression plots between mean ~nacroalgal index and (A) mean herbivore density (no. individuals/100m'), (B) mean herbivore biomass (grams/loom'), by site in Maria la Gorda, Cuba. Relatively high values for the species diversity indices were found during the qualitative fish surveys at Maria la Gorda (Table 2). Moreover, the total number of species recorded in the "all species" transects (42 to 54, n = 6 sites) was slightly higher than the value in the Archipidlago 10s Canarreos (mean = 42, sd = 5, n = 21 sites) recorded in (Instituto de Oceanologia database). The most frequently sighted and abundant of these species (blue chromis, bicolor damselfish, and bluehead wrasse) are common dominants in many other Cuban coral reefs (Claro and Garcia-Arteaga, 1994; Claro et al., 1998; Claro and Parenti, 2001). Small-sized species of parrotfishes and grunts dominated the AGRRA fishes in belt transects at the two shallower reefs. Total fish biomass in Maria la Gorda was low

9 "all species" census were approxin~ately 30% lower than those at comparable depths in the Archipidago 10s Canarreos and Archipielago Sabana-Camaguey in and less than 50% ofthat recorded for the Archipidlago Jardines de la Reina in 1997 (Claro and Parenti, ). Herbivore biomass was 37% lower in Maria la Gorda than that hund in 1996 in the marine reserve at the Archipielago Jardines de la Reina, where larger-sized species are morc abundant (Sierra et al., 2001). Nevertheless. the densities and biomass of herbivorous fishes in Maria la Gorda were higher than those recorded at the Archipidago 10s Canarreos (Table 6) and at the Archipielago Sabana-Camaguey in , and even exceeded corresponding values [or Martinique, Gundeloupe. and Key M'est. Florida (Clnro and Parent; ). I'hc mean biomass of'carnivorous fishes (selected groupers and snappcrs) \\as \. er? low: \ alues were about eight times higher in the "all species" sun eys at -2rchipiilago 10s Cailarrcos ( I'able 6). 13articularl! notable as the scarcity of snappers. r+hich arc usuallg common in Cuban reefs (Claro and Garcia-Arteaga, 1994; C'laro et al., 1998). I:or esainple, average smpper biomass at the Archipielago 10s Canarreos in i was thirteen timeb higher than that found in 1999 off Maria la Gorda. The slight11 higher abundance and size of carnivores in one of its deeper reefs (D-1) may result in part from the higher relief and topographic complexity at its edge, where snappers and black durgeon tend to aggregate. Medium- to large-sized species of fishes were uncommonly scarce off Maria la Gorda. Habitat conditions (live stony coral cover, topographic relief and complexity, water quality, etc.) in 1999 seemed excellent and capable of supporting much higher fish densities. Anecdotal information and qualitative information (personal observations os the senior author) during the 1970s and 1980s indicate that Maria La Gorda3s fish populations, especially the snappers and groupers. are drastically reduced. Indeed. this area, along with Cabo San Antonio at the westernmost edge of the Biosphere Reserve. had been well known for its abundance of large fishes. Management objectives for the Biosphere Reserve are intended to protect its natural resources, to attract tourists, and to serve as reproductive replenishment reserves for downcursent reefs; yet it is clear that fishing regulations here are poorly enforced. Large-sized fishes are vulnerable even to very low harvesting levels (Watson et al., 1997). Furthermore, fish that are subjected to spearfishing are likely to swim away from divers, which further diminishes the reserve's touristic value. Removing large predators alters a reefs trophic balance, potentially allowing small territorial fishes and invertebrate predators of scleractinians, such as the snail, Corcrlliophila abbreviata, and the bristle worm, Hermodice carunculata, to proliferate. Indeed, along with blue chromis, loreto (Gramma loreto), and bluehead wrasse, the density of damselfishes at Maria la Gorda was eightfold greater than had been found in the Archipelago 10s Canarreos in , and the bicolor damselfish was 13 times more abundant (Claro, unpublished data; Table 5 for damselfishes). Individuals of the three-spot damselfish (Stegastesplan2frons) were conspicuously destroying live corals in order to construct algal gardens with which to defend their territory and attract females. Fishing the larger-sized herbivorous parsotfishes can also have unintended consequences

10 when macroalgae znd turf algae increase in aburidance, as may ha Maria la Gorda (Alcolado et al., this volume). For all of these reasons, it is very important that the regulation prohibiting fishing at Maria la Gorda be strictly and effectively enforced. We also recommend increasing the no-take area protected from commercial fishing, educating the professional dive guides about the ecological and economic value of intact residential fish populations, and periodic monitoring of the local fish communities. Furthermore, the commercial and sport fishing that is carried out nearby at Cabo Corrientes during the fish spawning aggregations should be completely suspended. Establishing a carefully self-regulated ''catch and release" fishery for certain non-reef fishes (tarpon, bonefish) should be considc.red as an alternative source of revenue for displaced fishers. The AGIiRA organizing Committee, which facilitated financial support as described in the Forward to this volume is thanked for the invitation to collaborate in this regional initiative. We acknowledge the invaluable collaborations with, and support from, Reef Relief. Claro, R., and L.R. Parenti The marine ichthyofauna of Cuba. Pp In: R. Claro, KC. Lindeman and L.A. Parenti (eds.), Ecology ofthe ~Varine Fishes ofcuba. Washington, D.C., Smithsonian Institution Press. Claro, R., and M. C. Lindeman In press. Identification of snapper and grouper spawning aggregation sites on the insular shelf of Cuba. Proceeding ofthe Gulf and Curibbean Fisheries Instittrte 54th Annual Meeting. CIaro, R., and J.P. Garcia-Artega Estructura de las comunidades de peces en 10s arrecifes del Grupo Insular Sabana-Camaguey, Cuba. Revista de Oceanologia y Ecologia Tropical Avicennia 2: Claro, R., J.P. Garcia-Artega, Y. Bouchon-Navarro, M. Louis, and C.Bouchon Caracteristicas de la estructura de peces en 10s arrecifes de las Antillas Monores y Cuba. Revista de Oceanologia y Ecologia Tropical Avicennia 8/9: Eschmeyer, W.N. (editor) Catalog offishes. Special Publication No. 1 of the Center for Biodiversity Research and Information, California Academy of Science, San Francisco, CA. Volumes 1-3,2905 pp. Garcia-Arteaga, J.P., R. Claro, and S. Valle Length-weight relationships of Cuban marine fishes. NAGA, ICLARM Q. 20(1):38-43.

11 Humann, P ReefFish Identfication, 2nd ed. New World Publications, Inc., Jacksonville, FLY 424 pp. Watson, M., R.F.G. Ormond, and L. Holliday The role of Kenya's marine protected areas in artisanal fisheries management. Proceedings of the Eighth International Coral Re~f Syrnposiunz, Panama 11:

12 - Table 1. Site information for AGRRA fish surveys in Maria la Gorda, Cuba. Site name Site Reef type l,at.~tude Longitude Survey datc Depth 0 I ) % Il~e ston) Macroalgal AGRRA code (" (O '1 (m) coidl cover mdex' 50 1n fish (nican + sd)' -. transects (#) Yemayi I Sh-1 Fringing lobe July 8, _; Acuario I Sh-2 Fringing lobe July t Jardin de las Gorgonias I D-1 Fringing spur July i La Cadena Misteriosa -D-2 Fringing spur July i ' from Alcolado et al. (this volume). Table 2. Species numbers in the surveys in Maria la Gorda, Cuba; species indices based om roving diver surveys. Site code Sh-1 D- 1 D-2 C All sites ~... ~ Species number Species indices Belt transects Roving diver Diversity Richness Evenness A GRRA "All species" surveys (1-1 ') (Ri) (1) I

13 Table 3. Twenty-five most frequently sighted fish species during rover diver surveys in Maria la Gorda, Cuba, with mean density for species in AGRRA belt transects Species name Ranking index' Sighting frequency Density (%)3 (#I100 rn') 1 ('hiretodon c~,~~~.~fratzts 'Species names according to Eschmeyer's (1998) revision. a an kin^ index = (% sighting frequency x % abundance. 'Sighting frequency = percent of all roving diver surveys in July, 1999 in which the species was recorded.

14 Table 4. Sighting frequency and density for the twenty-five species highest in the hierarchy index in AGRRA belt transects in Maria la Gorda, Cuba. Speci- LS name Scarris iserti (=S. civicensis) I A ccr17thurri.r coeru1err.r Chaetodo17 cupistratus Sparisornu viride Ifaeinulot~ S C ~ Z ~ S Melichthys 17 ipi..c~.arri.~ tne?liopterz~s Cepiialopho1i.s cruetitatn Spczrison7a chrw)ptei~ziin Spari.soi?ia cmrofienarum?,4ie~.osl~i~ti?od0/7 c~?~j:\'su~ws Scar us vetziln Ocyrrus ch~ysurus Accmthurzis chirurgus Cel~phalopholisji~lva (=~~ine~helusfulvus)' Hae~milon plzmieri Spariso~iia atotnarium Baiistes vetula Ho1acanthu.s ciliuris Lutjanus ~podzrs Acai~thurus bahianzis A4ycteroperca lipis Pomacaizthus paru Bodiatl us rufiis 'species names according to Eschmeyer's (1998) revision. '~ierarch~ index = % sighting frequency x % density. Hierarchy Sighting Density index' frequency (li1100 "1') I

15 Table 5. Density of AGRRA fishes, by site in Maria la Corda, Cuba. Site code Sh-I Sh-2 D- l D-2 All sites Density (#/I 00 n?) Herbivores Carnivores Others Total -- Acanthuridae Scaridae micros path odor^ I-lnemulidae Lutjanidae ~ersnnidae' (25 cm) chr)aurus (25 cm) l I.83 n -? * 6.9 'Epinephelus spp. and AGcteroperca spp. Table 6. Mean density and biomass of "all species" in Maria la Gorda (this study) and Los Canarreos (in ). Taxon and parameter '~erbivore density (#/I00 m2) Herbivore biomass (dl00 m2) 'snapper and grouper density (#I100 mz) Snapper and grouper biomass (dl 100 m2) Damselfish density (#/lo0 m2) Bicolor damselfish density (#/lo0 m2) Total fish density (#I100 m2) Total fish biomass (g/100 m2) '~erbivore Canarreos (I , n=l6 reefs, depth=15 m) Maria La Gorda (1 999, n-4 reefs. depth-5-13 m) = all herbivores; 'snapper and grouper = all species of lutjanids and senmids ,800 3, , I IS k 12,432 8,620

16 Table 7. Biomass of AGRRA fishes, by site in Maria la Gol-da, Cuba. Site code Sh- 1 Biomass (dl 00 m2) - Herbivores Carnivores Others Total Acanthuridae Scaridae Micr-ospalhodon Haemulidae Lutjanidae ~crr-anidael (25 cm) chryszirus (25 cm) ,794 D All sites , ,987 f 2,380 'Epinephelus spp. and A4ycferoperca spp.